1. Technical Field
Methods and apparatuses consistent with the present invention relate to scalable video coding, and more specifically, to scalable motion vector coding by providing motion vector with scalability, i.e., adjusting the amount of bit allotted to motion vector and coding motion vector residual based on Context Based Adaptive Binary Arithmetic Coder (CABAC).
2. Related Art
In scalable video coding, bitstream is generally divided into motion vector information (motion vector, divided block map, etc) and texture information including residual obtained by motion estimation. Motion information is losslessly compressed. However, currently used motion vector coding in the context of scalable video coders collects all the motion information together and places it at the beginning of the compressed bitstream. Because it contains the motion vectors at the highest frame rate and for the best image quality, this portion of data takes a large amount of bits. Hence, the coding performance at low bit-rates is relatively poor because the truncated bitstream contains mostly the motion information. Thus, there is a need for dividing motion information according to its importance and transmitting a portion of motion vector depending on channel condition in the context of scalable video coders.